It takes significant investment of time to become proficient with a user interface of a particular application. With increasing numbers of devices and operating systems, users are often forced to learn new user interfaces when moving between systems and applications. For example, a user may be most familiar with a Microsoft Word user interface for a word processing application. But, at work or on their portable device, they might have to use another word processing application, for example, Open Office or Google Docs. Learning the user interface of the second word processing application may waste time and decrease productivity.